Oil burner and operation thereof



Feb. 19, 1929.

C. M. ALEXANDER Filed Feb. 26,A 1926 OIL BURNER AND OPERATION' THEREOF ATTORNEYS Vthe liquid fuel.

Patented Feb. 19, 1929.

PATIENT OFFICE.

OLIVE M. ALEXANDER, OF TULSA. OKLAHOMA. A

OIL BURNER AND OPERATION THEIR/EOF.

Application I-ed February 26, 1926.

My invention relates to improvements in regulation of oil burners, and although of general utility is of special value and application in handling viscous fuel oils or fuel oils containing large proportions of suspended solid or semi-solid matter. v

In the conventional type of oil burner, a throttle valve is commonly employed in the fuel supply line for controlling the supply of With fuel oils of high viscosity or with fuel oils containing much suspended matter, such throttle valves offer difficulties which will be apparent and which have been a serious handicap in the convenient and eectiveutilization of fuels of this character. Clogging, for example, is a difficulty lfrequently encountered, andthe operation also tends to be irregular and difficult ofcontrol.

A liquid fuel in utilization of which these difficulties are encountered to a marked extent and to which my invention is particularly applicable is the residuum withdrawn from many of the so-called cracking processes which are in commercial use. This residuum is usually of a heavy tarryv nature and frequently contains large proportions of suspended matter, and consequently has been considered less desirable as a fuel than other more expensive fuel oils.

According to my invention, I control the supply of liquid fuel to the oil burner by intermixing a gaseous medium with the fuel and regulating the proportion of. this gaseous medium so introduced in admixture with the fuel while causing this mixture to flow to the burner through a conduit of ysubstantial v length but of restricted cross-section. Ihave thus found it possible to eliminate any necesvsity for using throttle valves in the fuel supply line as Il can effect control of the burner simply by means of a valve in the line through which the gaseous medium is supplied. I thus secure convenient and ready control of the operation and can also secure improved uniformity in operation, particularly when burning viscous fuels or fuelscon taining large proportions Aof suspended matter. f I am not'entirely. able to explain the results I secure, although it seems that several factors are involved. With iixed conditions of pressure, the relative proportion of oil flowing to-v the burner would apparently be decreased by increasing the proportion of gas flowing Y of my invention.

Serial No. 90,755.

therewith through the conduit to the burner. The foam or emulsion of fuel oil and gas resulting from the intermixture may also have an increased resistance to flow which iiow resistance varies with the proportion of gas present. In passing through the conduit between the point of introduction of the gaseous medium and the burner, control of the iiow resistance would afford control of the flow of fuel oil. Likewise, the gaseous medium may have a throttling effect at the point of introduction obstructing the flow of fuel oil similarly to a partially closed valve but without being subject to the difficulties encountered in theuse of avalve of ordinary construction.

kThe exact method of introducing the gaseous medium in carrying out my invention may be varied. It may, for example, be introduced through perforations or a peripheral slit in the conduit leading to the oil burner, and these perforations or this slit may be arranged to introducevthe vgaseous medium in a direction normal to the axis of the conduit or at an angle inclined against the direction of flow of fuel oil through the con duit. Among the gaseous mediums useful in carrying out my invention are steam, air and flue gases. Gases which take part in the combustion or gases which are inert' therein, combustible or non-combustible gases, may be employed. Either wet or super-heated steam may be used, for example, exhaust steam -from an engine may be employed for the purposes In any event, the gaseous medium is introduced into the conduit communicating with the burner at apoint spaced from the point at which the conduit connects with the burner so that the resulting mixture of gas and oil must flow through a substantial length of the conduit.

I will describe my invention further in connection with the accompanying drawings which illustrate, diagrammatically and conventionally, apparatus embodying my invention and adapted for carrying out my invention. It will be understood that this further illustration and description are for the purpose of the exemplification of the invention and that the invention is not limited thereto.

In the accompanying drawings:

F ig. l represents in elevation, and partly in section with parts broken away, an oil burner assembly embodying the invention and adapted for operation in accordance with the invention.

Fig. 2 is an enlarged section of the mixing means illustrated in Fig.. 1, and

Figs. 3 and al are similar sections of modified forni of the mixing means.

Referring to the drawings, fuel oil is supplied to connection 5, the gaseous control medium through connection 6, and the gaseous medium for effecting the major part of the spraying or jetting of the fuel oil through connection 7. The fuel oil flows first through the mixing chamber 8 and then through the elongated conduit 9 to the burner proper being discharged through the opening 10 at the end of the conduit 9. The gaseous medium for sprayingor jetting the fuel oil enters chamber 11 from which it is discharged to the burner nozzle 12 with the fuel oil escaping from the opening 10. rlhe gaseous control medium enters the chamber S from which it is introduced into the conduit 9 through perforations 13. lt this point'this gaseous medium is intermiired with the fuel oil and t-he re* sulting mixture confined within the conduit 9 and compelled to flow theretlnfough together to the point of discharge 10. The gaseous control medium is supplied under a pressure somewhat exceeding that maintained on the fuel oil and the supply of this gaseous medium may be cont-rolled, for example, by the valve 14.

In the modified forinof the mixing means illustrated in Fig. 3, the perforations 18a, nstead of being arranged to direct streams of the control medium in a direction normal to the axis of the conduit 9 as in Fig. 2, are arranged to direct streams of the control medium against the flow of the fuel oil. In the mixing means illustrated in Fig. Ll, the gaseous cont-rol medium is introduced through a peripheral slit 15. This slit is arranged to introduce the control medium in a direction against the flow of the fuel oil, and the width of the slit is made adjustable by means of the collar 16.

In carrying out my invention in the apparatus illustrated in Fig. 1, the valve 14 is first opened and the control medium is adinitted through connection t5 to the chamber 8 from which it escapes from the perforation 13 to the conduit 9. Valve 17 is then opened wide to avoid any tlirottling of the fuel oil and the fuel oil flows through connection 5 and then through conduit 9 in intermixture with the gaseous control medium entering through perforations 13. The flow of fuel oil to the burn er is then controlled by regulating the valve 1st to control the proportion of gaseous medium introduced into the conduit 9 through the perforations 13. Additional gas for spraying and jettiug the fuel oil and for controlling the operation of the burner, with respect to factors such as the length of the llame, is admitted through connection 'i' as may be required.

lt will be apparent that l thus accomplish effective control of the supply of fuel oil and of the operation of the burner without throttling of the liquid fuel. The objections ineioent to the provision and operation of a throttle valve are thus eliminated by my invention.

l have successfully employed my invention in burning hydrocarbon tar contaicing` from 60 to 70% of suspended carbon. rllhe liquid, or semi-liquid fuel may he supplied under from 10 to 2() pounds gage pressiue and the gaseous control medium may he supplied to the chamber of the mixing means under a pressure of from 50 to 10G pounds ln the burning of relatively thin liquid fuels, pressures as low as 5 pounds per square inch in the fuel may be used, and with very heavy or very viscous fuels pressures as high 40 to 50 pounds per square inch or more may be employed with advantage. rlhe pressures to be employed in any particular case will depend somewhat upon the nature of the fuel being burned, but in general higher pressures are employed with heavier or more viscous liquid fuels with a conduit of the same dimension connecting the mixing means and the burner propel'.

I claim:

1. An improved method of controlling the flow of fuel oil to an oil burner, comprising supplying the fuel oil to the burner through an elongated conduit, introducing a gaseous medium into the conduit at a point a substantial distance from the point of discharge from the conduit in sufficient quantity so that any increase will result in a decrease in the amount of oil flowing through said conduit, whereby the gaseous medium and the fuel oil are intermixed and caused to flow in admixture through the conduit to the burner, and controlling the flow of liquid fuel by regulating the proportion of the gaseous medium caused to flow through the conduit in inter-A mixture therewith.

2. An improved method of controlling th flow of fuel oil to an oil burner, comprising supplying the fuel oil to the burner through an elongated conduit, introducing a gaseous medium into the conduit at a point a substantial distance from the point of discharge from the conduit in suh'icient quantity so that any increase will result in a decrease in the amount of oil flowing through said conduit, whereby the gaseous medium and the fuel oil are intermiXed and caused to flow in adminture through the conduit to the burner, and controlling the flow of liquid fuel exclusively by regulating the proportion of the gaseous medium caused to flow through the conduit in intermixture therewith.

3. An improved method of controlling the liow of fuel oil to an oil burner, comprising supplying the fuel oil to the burner through an elongated conduit, introducing a gaseous medium into the conduit at a point a substantial distance from the point of discharge from .the conduit, and in a direction opposed to the How of liquid fuel through the conduit, and controlling the flow of liquid fuel by regulating the proportion of the gaseous medium caused to iioW through the conduit in intermiXture therewith.

4f. An improved oil burner assembly, comprising a burner nozzle and an elongated oil supply conduit adapted to discharge through said burner nozzle, means adapted to supply a gaseous medium directly to said burner nozzle and for spraying a liquid fuel With said gaseous medium, separate means for forcing a gaseous medium into said conduit at a point a substantially greater distance from the discharge end of said conduit than the distance between the discharge end of said burner nozzle and the discharge end of the said supply conduit, and means for independently controlling tlie proportion of gaseous medium forced into said conduit.

5. An improved oil burner assembly, comprising a burner nozzle including means for spraying liquid fuel with a gaseous medium, an elongated oil supply conduit adapted ,to discharge to said burner nozzle, means for injecting a gaseous medium into said conduit at a plurality of points around the periphery of said conduit a substantial distance from the discharge end of said conduit and at an angle of at least 90 to the direction of flow of oil in the conduit approaching said injecting means, said injecting means being separate and i n addition to the means for spraying the liquid With a gaseous medium, and means for controlling the proportion of gaseous medium forced into said conduit.

In testimony whereof I affix my signature.

OLIVE M. ALEXANDER. 

